#define _CRT_SECURE_NO_WARNINGS
class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
        set<int> st1(nums1.begin(), nums1.end());
        set<int> st2(nums2.begin(), nums2.end());
        vector<int> v;
        auto it1 = st1.begin();
        auto it2 = st2.begin();
        while (it1 != st1.end() && it2 != st2.end())
        {
            if (*it1 < *it2)
            {
                it1++;
            }
            else if (*it1 > *it2)
            {
                it2++;
            }
            else {
                v.push_back(*it1);
                it1++;
                it2++;
            }
        }
        return v;
    }
};